Flank pain: Difference between revisions
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*Serum uric acid level and Serum calcium level: The levels are measured if a urinary calculus is suspected. | *Serum uric acid level and Serum calcium level: The levels are measured if a urinary calculus is suspected. | ||
*Beta hCG test: It is done to confirm or rule out a pregnancy in reproductive age group females. | *Beta hCG test: It is done to confirm or rule out a pregnancy in reproductive age group females. | ||
*Miscellaneous: Anti nuclear antibody, perinuclear anti neutrophil and cythoplasmic anti neutrophilic antibody, protein C and protein S levels, Factor V Leiden mutation, anticardiolipine antibody IgM and IgG, antithrombine 3 activity, B12 vitamine, folic acid, homocysteine levels. | *Miscellaneous: Anti nuclear antibody, perinuclear anti neutrophil and cythoplasmic anti neutrophilic antibody, protein C and protein S levels, Factor V Leiden mutation, anticardiolipine antibody IgM and IgG, antithrombine 3 activity, B12 vitamine, folic acid, homocysteine levels are done to rule out differential diagnosis. | ||
*Blood and Urine culture: Positive urine culture shows growth of ≥ 105 colony-forming units per mL of urine. Positive blood culture is found in 15 to 30 percent of cases. | *Blood and Urine culture: Positive urine culture shows growth of ≥ 105 colony-forming units per mL of urine. Positive blood culture is found in 15 to 30 percent of cases. | ||
*Peripheral blood film: It show leukocytosis with or without left shift. | *Peripheral blood film: It show leukocytosis with or without left shift. | ||
Revision as of 16:39, 2 December 2020
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1],Associate Editor(s)-in-Chief: Jaspinder Kaur, MBBS[2]
Overview
Flank pain is a sensation of discomfort, distress, or agony in the part of the body below the rib and above the ilium, generally beginning posteriorly or in the midaxillary line and resulting from the stimulation of specialized nerve endings upon distention of the ureter or renal capsule. Flank pain often is due to a urologic etiology, such as renal calculus disease or acute pyelonephritis; however, cardiac, intraabdominal, musculoskeletal, and psychological causes also need to be considered. The quality and severity of the pain may provide a clue to its etiology. Flank pain that is due to infection, such as acute pyelonephritis, usually is steady and dull, whereas pain that is due to an acutely obstructing calculus can be intense and sharp. The kidney and its capsule are innervated by sensory fibers traveling to the T10-L1 spinal cord. Pain that originates from the kidney often is felt just lateral to the sacrospinalis muscle beneath the 12th rib posteriorly. The pain often radiates anteriorly, but it also may be referred to the inguinal, labial, penile, or testicular areas. Flank pain that originates from urinary tract pathology may be caused by obstruction, inflammation, or mass. When evaluating a patient with flank pain, the severity of the pain generally correlates inversely with the duration of the problem. That is, chronic, gradual distention of the renal capsule over a long period of time due to a slowly enlarging ureteral tumor often is associated with mild to moderate flank pain. The pain is mild or dull because it results in gradual but possibly severe distention of the renal collecting system and capsule. In contrast, the acute flank pain that is associated with an obstructing renal calculus often is severe, since it results in sudden distention of the renal collecting system and capsule. Severe flank pain caused by an acute urinary tract obstruction is termed renal colic. It is important for the clinician to determine if the pain represents an emergency or if the problem can be managed in the outpatient setting.In this regard, it is important to determine if there is associated fever, dehydration, nausea, or vomiting. Comorbid medical conditions, such as diabetes, immunocompromise, or pregnancy, also need to be considered. When flank pain presents in association with any one of these factors, hospital admission may be necessary to prevent possible complications, such as pyelonephritis or urosepsis, from developing.
Pathophysiology
Flank pain originating in the urinary system is caused by distention of the ureter or renal pelvis or distention of the renal capsule. The severity of the pain is directly related to the rapidity of the distention and not to the degree of distention. Therefore, a patient with acute distention of the ureter will have extremely severe pain. This patient usually has mild dilation of the ureter and no irreversible renal damage. However, a patient with a greatly dilated ureter and irreversible renal damage might have no pain or mild pain because the ureteral dilation has developed over a long period of time. Distention of the renal capsule causes a milder flank pain. This can be caused by aucte pyelonephritis, ureteral obstruction, or renal subcapsular hematoma. Kidney and ureteral pain is through visceral afferent fibers that accompany the sympathetic nerves of the lower thoracic and upper lumbar segments.
Flank pain due to ureteral obstruction: Flank pain that radiates to the ipsilateral testicle is usually caused by proximal ureteral or renal pelvic obstruction due to the common innervation of the testicle and the renal pelvis (T11–12). This pain usually originates in the posterior part of the flank and radiates to the testicle of the male or the labia of the female. The pain becomes lower and more anterior in the flank when the obstruction occurs in the middle third of the ureter. The pain is still lower, radiates to the scrotal skin (rather than the testicle), and is associated with voiding symptoms such as urinary frequency and urgency when the obstruction occurs at the level of the ureterovesical junction.
The degree of severity of the pain is directly related to the acuteness of the obstruction rather than the degree of obstruction. Therefore, a stone that passes into the ureter and suddenly becomes lodged in one position usually causes extremely severe pain. But flank pain can be very mild or absent in the presence of very severe but chronic obstruction. Mild and chronic flank pain associated with severe ureteral obstruction can produce irreversible renal damage. A stone passing through the ureter will often cause severe but intermittent pain. The intermittent pain is related to obstruction produced when the stone becomes lodged in the ureter. Therefore, each episode of pain is likely to be associated with a stone becoming lodged in a new and more distal position in the ureter. Flank pain is often associated with less specific symptoms including fever, nausea and vomiting, and tachycardia. Fever suggests infection proximal to the ureteral obstruction. Flank pain associated with fever requires a prompt diagnosis of ureteral obstruction and relief of the obstruction because infection proximal to the obstruction causes much more rapid renal damage than occurs with obstruction in the absence of infection. Also, the patient is susceptible to septicemia in the presence of infection proximal to a ureteral obstruction.
Gross or microscopic hematuria helps to confirm a urinary cause of the pain. Hematuria is occasionally absent with acute ureteral obstruction, however, and is often absent with chronic obstruction.
Congenital anomalies related flank pain Congenital anomalies such as ureteropelvic junction obstruction produce flank pain associated with a diuresis after oral intake of a large volume of fluid. Bilateral chronic ureteral obstruction or ureteral obstruction of a solitary kidney can be associated with symptoms of renal failure such as apathy, lethargy, anorexia, muscle twitching, headache, hypertension, and poor growth of a child. A dull or mild flank pain should make the clinician consider many possible causes including congenital ureteral obstruction, ureteral tumor or an extrinsic tumor compressing the ureter, acquired stricture of the ureter due to a previous operation or radiation therapy, retroperitoneal fibrosis, and a ureteral stone.
Extraurinary disorders related flank pain These diseases produce pain less characteristic of the typical "renal colic" seen with acute ureteral obstruction. Nevertheless, this vague, dull, mild flank pain is similar to the pain seen with chronic ureteral obstruction, making the differential diagnosis unclear. The correct diagnosis is made by thinking of all the diseases that have been discussed, considering the associated symptoms, physical examination, urinalysis, and performing carefully selected laboratory tests and radiographic studies.
Causes
- The etiology of flank pain is multifactorial which includes from local, systemic, metabolic to underlying genetic factors. Depending upon the etiology in association with other comorbidities, it is determined to treat the patients in an outpatient or hospital setting; as life-threatening causes may result in death or permanent disability within 24 hours if left untreated.
Table: List the most common and life threatening causes of flank pain
Life Threatening Causes
Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.
- Acute tubular necrosis
- Ischemic colitis
- Ovarian torsion
- Renal abscess
- Renal artery dissection
- Renal cyst rupture or hemorrhage
- Ruptured abdominal aortic aneurysm
- Renal vein thrombosis
Flank pain developed by WikiDoc.org
Common Causes
- Abdominal muscle spasm
- Acute pyelonephritis
- Nephrolithiasis
- Polycystic kidney disease
- Renal cyst
- Urinary tract infection[1][2][3]
Flank pain developed by WikiDoc.org
Causes by Organ System
Flank pain developed by WikiDoc.org
Causes in Alphabetical Order
Flank pain developed by WikiDoc.org
Differential Diagnosis
Epidemiology and Demographics
- Men are more commonly affected than women, and the incidence increases with age until age 60 years. Children are affected less frequently.
Risk Factors
Table: List the risk factors for flank pain
| Urinary conditions | Extra-urinary conditions |
|---|---|
|
|
Screening
Natural History, Complications, and Prognosis
Diagnosis
History and Symptoms
- The history is the most important component of the evaluation of the patient with flank pain.
- Onset and severity:
- Acute and severe pain is characteristic of renal colic and most commonly results from an acute obstruction of the urinary tract due to a calculus.
- Chronic and dull pain is more typical of an infectious, malignant, or congenital problem.
- Nausea and Vomiting: These symptoms are due to irritation of the peritoneum and distention of the renal capsule. Nausea and vomiting, therefore, can occur with most causes of flank pain; however, it is most severe when the flank pain is acute and severe, such as from a renal calculi.
- Urinary frequency and urgency: It is more likely due to pain that is referred to the bladder area.
- Gross hematuria: It mandates a complete urologic evaluation to rule out a malignancy of the urinary tract, such as a renal carcinoma, bladder carcinoma, or ureteral tumor. The evaluation should include imaging of the upper urinary tract with ultrasound or CT scan and evaluation of the bladder with cystoscopy.
- Fever: It is an ominous sign that usually indicates infection. The source of the fever typically is infected urine that remains undrained behind the source of obstruction, such as a calculi, stricture, or tumor. If no obstruction is present, yet the patient complains of flank pain in the presence of fever, it is consistent with acute pyelonephritis. In this situation, the renal tissue itself is infected, without obstruction of the urinary tract collecting system.
- Comorbid conditions: Such conditions might predispose an individual to developing urosepsis.
- Tobacco use: It's use should be determined, since it increases the risk for developing a transitional cell carcinoma. The tumor or a blood clot formation from gross hematuria can cause obstruction and causes flank pain identical to that produced by a renal calculi.
- Cardiac arrhythmias: It can presents with acute, severe flank pain due to underlying possible thromboembolic event. In this situation, a cardiac thrombus suddenly is dislodged and obstructs the main renal artery or one of its branches. The resulting pain is identical to that produced by a renal calculi, so a history of cardiac arrhythmia is essential for establishing the diagnosis. A functional imaging study, such as an IVP, contrast-enhanced CT, or renal angiogram, demonstrates absence of renal blood flow, indicating obstruction of the renal artery.
Physical Examination
- A complete physical examination is indicated for patients presenting with flank pain to help determine the etiology of the pain and the severity of the problem to resist the focus on the urinary tract or flank area exclusively.
- Vital signs: They are important to determine the association with dehydration, infection, or urosepsis.
- Urosepsis: In the patient with flank pain, urosepsis is suggested if the patient is febrile, has a rapid pulse and respiration rate, and has labile blood pressure. If urosepsis is suspected, the patient should be hospitalized to prevent septic shock. In this situation, intravenous antibiotics, aggressive fluid replacement, and urologic relief of any hydronephrosis are indicated.
- Urinary tract infection: Fever from a lower urinary tract infection (bladder) may be low grade, while high spiking temperatures suggest upper tract infection (kidney). It is important to note, however, that one always cannot localize the site of the infection by the severity of the temperature. That is, a high temperature necessarily does not indicate upper urinary tract infection and vice versa; this is true especially in children.
- Carotid arteries: They should be auscultated for bruits to evaluate for a possible cardiac etiology of the flank pain, such as a renal artery disease or embolus.
- Heart auscultation: Heart rate, rhythm, and murmurs should be listened for underlying renal artery embolism usually occurs in patients with atrial fibrillation.
- Abdomen: It should be examined for bruits, tenderness, and masses. If the pain is more severe during the abdominal examination, consider intraabdominal etiologies for the flank pain.
- Rectal examination: It should be done with stool for guaiac to exclude a possible intraabdominal cause for the flank pain.
- Genital examination: It should be done in both males and females since referred pain is common. The bladder sometimes is able to be palpated just above the pubic symphysis. If the bladder is distended, it suggests a possible urologic etiology for the pain. In females, it is essential to determine if the patient is pregnant with a urine or serum b-human chorionic gonadotropin (b-HCG) test. If the patient is pregnant, x-rays should be avoided, and the patient should be evaluated with ultrasound.
- Flank area: It should be examined for asymmetry, mass, and percussion tenderness. It is uncommon to discover a palpable flank mass, unless there is a large renal tumor present. Patients with acute pyelonephritis or obstructing renal calculi complain of severe pain when the flank is percussed, so it is important to tap lightly in order to maintain patient confidence.
- Lower extremities: To rule out a musculoskeletal etiology for the flank pain, the lower extremities should be examined for motor and sensory function.
Laboratory Findings
- Urinalysis:
- Initial diagnostic test.
- Parameters to be considered: pH, WBCs, RBCs, bacteria, casts, and crystals
- High (alkaline) pH: Infected urine secondary to urea splitting bacteria
- Acidic pH: Patients with uric acid stones tend to have an acidic urine, since these stones do not form when the urine is alkaline.
- WBC: The presence of WBCs in the urine may signify infection, but it also may be due to inflammation caused by a stone. The presence of WBC casts strongly suggests urinary tract infection or acute pyelonephritis.
- RBC: Tumors of the urinary tract usually result in urinary RBCs, and the urine may appear grossly bloody. A stone similarly can result in RBCs in the urine, so it is important to repeat a urinalysis in patients after they have passed the stone to exclude an underlying urologic cancer. If the patient has RBCs in the urine after the stone has passed, urologic evaluation is necessary.
- Gram stain: It should be done in the emergency room or clinic and can help determine if infection is present. In the case presented, a negative Gram stain suggests sterile urine. Finding bacteria on an unspun specimen suggests infection. Most urinary tract infections are caused by gram-negative bacteria such as E. coli; however, gram-positive organisms can cause urinary tract infections as well. If urinary calculi are present within the urinary tract, it is not uncommon to find crystals in the urine analysis, along with RBCs and WBCs.
- Crystals: The shape of the crystal can be used by the laboratory technician to help identify its composition.
- The urinalysis may be normal if the etiology of the flank pain is due to cardiac, intraabdominal, musculoskeletal, or psychological problems.
- Complete Blood Count:
- If the serum WBC count is elevated, infection is suspected.
- Anemia and a low or high platelet count might be seen in the presence of bleeding urologic tumors.
- An abnormally high hematocrit can be seen if the patient is dehydrated.
- Serum blood urea nitrogen (BUN):
- An elevated BUN can be due to renal disease or dehydration.
- In general, if the BUN is greater than 10 times the serum creatinine level, then the elevation most likely is due to dehydration.
- If the BUN to serum creatinine ratio is 10 or less, then renal disease is likely.
- Serum creatinine:
- It level directly reflects renal function.
- An elevated creatinine indicates impaired renal function, regardless of the BUN value. The impaired function could be due to dehydration, obstruction, tumor, infarct, or medical renal disease. Moreover, an elevated serum creatinine indicates bilateral renal disease or disease involving a solitary kidney, since only one healthy kidney is required to maintain a normal serum creatinine.
- Serum sodium: Hyponatremia results from volume overload and can cause nausea, vomiting, and seizures.
- Serum potassium: Hyperkalemia is dangerous, since it could result in cardiac arrhythmias.
- Serum bicarbonate: Its level falls in long-standing renal compromise along with hyperkalemia.
- Serum uric acid level and Serum calcium level: The levels are measured if a urinary calculus is suspected.
- Beta hCG test: It is done to confirm or rule out a pregnancy in reproductive age group females.
- Miscellaneous: Anti nuclear antibody, perinuclear anti neutrophil and cythoplasmic anti neutrophilic antibody, protein C and protein S levels, Factor V Leiden mutation, anticardiolipine antibody IgM and IgG, antithrombine 3 activity, B12 vitamine, folic acid, homocysteine levels are done to rule out differential diagnosis.
- Blood and Urine culture: Positive urine culture shows growth of ≥ 105 colony-forming units per mL of urine. Positive blood culture is found in 15 to 30 percent of cases.
- Peripheral blood film: It show leukocytosis with or without left shift.
X-ray
- A plain film of the abdomen can help identify urinary calculi. This film is called a KUB, since it visualizes the kidney, ureter, and bladder.
- The entire film should be viewed for intestinal gas pattern, gallstones, bony structure, and free air, which may provide insight into the etiology of the pain.
- Renal cell carcinomas are osteolytic tumors, and this can be seen radiographically in metastatic disease.
- An abnormal intestinal gas pattern, gallstones, or free air suggest intraabdominal pathology.
- Aortic calcifications and aneurysms should be determined, since they might suggest renal artery disease as the etiology of the flank pain.
- Urinary calculi typically are seen as calcifications overlying the kidney shadow or along the course of the ureter. Small stones, 1 to 2mm in size, can cause severe flank pain if they obstruct the flow of urine into the bladder. Stones typically become obstructive where the ureter meets the renal pelvis [ureteropelvic junction (UPJ)], where the ureter crosses over the pelvic brim, and where the ureter enters the bladder [ureterovesical junction (UVJ)]. Small stones tend to lodge at the UVJ, whereas bigger stones lodge higher in the urinary tract. It should be noted that uric acid calculi are radiolucent and are not seen on a plain film of the abdomen, but they can be seen on ultrasound or CT scan.
Intravenous pyelogram (IVP)
- The IVP is a relatively inexpensive functional study that diagnoses most urologic, infectious, and cardiac causes of flank pain.
- It requires the administration of iodine-based intravenous contrast medium; therefore, an allergic reaction to the contrast is possible. These reactions can be severe and have resulted in hemodynamic and respiratory collapse. To avoid contrast reactions, an ultrasound or noncontrast CT can be used instead of an IVP.
- However, if the clinician is concerned about a possible renal infarct secondary to an arterial embolus, a renal ultrasound and noncontrast CT scan might be normal, since they do not assess renal function. In this instance, the kidney looks normal; however, it is no longer functioning due to the recent infarct. To assess function, either an IVP or intravenous contrast enhanced CT scan could be done.
Echocardiography or Ultrasound
CT scan
CT Angiography
MRI
Other Imaging Findings
Other Diagnostic Studies
Treatment
Medical Therapy
Surgery
Primary Prevention
Secondary Prevention
References
- ↑ Wolffram, S.; Bisang, B.; Grenacher, B.; Scharrer, E. (1990). "Transport of tri- and dicarboxylic acids across the intestinal brush border membrane of calves". J Nutr. 120 (7): 767–74. PMID 2366111. Unknown parameter
|month=ignored (help) - ↑ Christodoulidou, M.; Thomas, M.; Sharma, SD. (2012). "Hydronephrosis and loin pain as a presentation of tubo-ovarian abscess developing after Mirena coil removal". BMJ Case Rep. 2012. doi:10.1136/bcr-03-2012-6108. PMID 22865801.
- ↑ Smith, HS.; Bajwa, ZH. (2012). "Loin pain hematuria syndrome-visceral or neuropathic pain syndrome?". Clin J Pain. 28 (7): 646–51. doi:10.1097/AJP.0b013e31823d47f3. PMID 22699133. Unknown parameter
|month=ignored (help)